Congrove Field and The Tumps is a is an 12.5 hectare

Hectare

The hectare is a metric unit of area defined as 10,000 square metres , and primarily used in the measurement of land. In 1795, when the metric system was introduced, the are was defined as being 100 square metres and the hectare was thus 100 ares or 1/100 km2...

 biological Site of Special Scientific Interest (SSSI) on Lansdown Hill, north of Bath in Bath and North East Somerset

Bath and North East Somerset

Bath and North East Somerset is a unitary authority that was created on 1 April 1996 following the abolition of the County of Avon. It is part of the Ceremonial county of Somerset...

, notified in 1991.

It is an area of calcareous grassland lying over Oolitic

Oolite

Oolite is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Hellenic word òoion for egg. Strictly, oolites consist of ooids of diameter 0.25–2 mm; rocks composed of ooids larger than 2 mm are called pisolites...

 (Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

) Limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 covered by shallow, well-drained soils. The Tumps is above Congrove Field, and is believed to be the site of mining activities in the past. The grassland communities present are of the Tor-grass

Tor-grass

Tor-grass is a plant in the grass family, with a widespread distribution in temperate regions of the Northern Hemisphere. It typically grows in calcareous grassland, and reaches 70–120 cm tall. The flowerhead is open, with 10 to 15 erect spikelets.The caterpillars of some Lepidoptera use it...

 (Brachypodium pinnatum) type showing elements of both the Meadow Oat-grass-wild thyme

Wild thyme

Thymus serpyllum, known by the common names of Breckland Thyme, Wild Thyme or Creeping Thyme is a species of thyme native to most of Europe and North Africa. It is a low, usually prostrate subshrub growing to 2 cm tall with creeping stems up to 10 cm long, with oval evergreen leaves...

 (Avenula pratensis)–(Thymus praecox) and the Knapweed-Rough Hawkbit (Centaurea nigra)–(Leontodon hispidus) variants.